Pedometer is a device capable of calculating the walking or running (hereinafter brief as walkrun) step number of its wearer. With more and more concern of the health condition of human beings, the pedometer becomes an aid for customizing sports schemes quantitatively, and has been widely used.
Currently, the pedometer is mainly divided into two types, mechanical pedometer and electronic pedometer. The mechanical pedometer generates electrical pulses through the vibration of internal reed or elastic ball of the pedometer caused by its wearer's walkrun, and counts the number of these electrical pulses through an internal processor, thus implementing the function of step counting. The cost of mechanical pedometer is relatively low, but the accuracy and sensitivity are poorer. The electronic pedometer is generally based on the output signal of an acceleration sensor to obtain its wearer's walkrun step number. The electronic pedometer is low in power consumption, and both its accuracy and sensitivity are superior to the mechanical pedometer. Therefore, the electronic pedometer becomes a hotspot in the current study of pedometer.
Human walkrun is a process with quasi-periodicity, therefore, although the accelerations generated in each direction during human walkrun are different, they all have the same quasi-periodicity, which is reflected by that the accelerations in different directions contain the same pitch. The pedometer based on acceleration sensor can produce an oscillatory acceleration signal during its wearer's walkrun and analyze the acceleration signal, to obtain the walkrun step number of its wearer. Specifically, the current pedometer based on acceleration sensor determines its wearer's walkrun step number according to the number of peaks of oscillatory acceleration signal it produces. The disadvantage of the step counting methods of these pedometers is in that the direct use of peaks of oscillatory acceleration signal to determine the walkrun step number can cause poor step counting accuracy, which will affect the implementation of sports scheme of the pedometer's wearer.